1. Field of the Invention
The present invention relates to a photoprinter which causes lengthy photosensitive material to correspond to a magazine used for loading the photosensitive material wound in layered form so as to control the relation therebetween.
2. Description of the Related Art
In a photoprinter, a large number of print channels have been provided therein. Coefficients and constants employed in the amount-of-exposure arithmetic expression are determined according to a selected print channel. The amount of exposure is controlled such that a printed photograph with proper density and satisfactory color balance can be obtained. The print channels are determined by a combination of paper balance, lens balance, film balance and the like. Paper balance represents the type of photographic paper. The paper balance is determined by a combination of its sensitivity, type of emulsions, type of surface, the manufacturer, the manufacturing serial number of the photographic paper, etc. The lens balance represents the type of lenses. The lens balance is determined by a combination of the printing magnification, F value of the aperture, etc. The film balance represents the type of a photographic film, for example, color negative film. The film balance is determined by a combination of the manufacturer, the sensitivity of the film, the size thereof, etc.
A conventional photoprinter is, however, accompanied by the drawback in that when the paper magazine with the photographic paper contained therein is changed, an operator operates the control panel to manually input the paper balance. This makes the operation for inputting the same cumbersome and liable to cause malfunction.
One proposal has therefore been made in which paper balance information representing the type of the photographic paper indicated at a port formed in the paper magazine by a combination of bar codes and the concave and convex is automatically read when the paper magazine is loaded. The printing condition of a printer is then changed in accordance with this information (see Japanese Laid-Open Patent Publication No. 62-106448). This disclosure permits an improvement in operational performance because manual operation becomes unnecessary.
In the above arrangement, when magazines are packaging containers or dedicated magazines, the indication of the respective photographic papers applied thereon is identical to the photographic papers contained therein. However, when they are refillable magazines, the operator may erroneously load the wrong photographic papers or fail to change the indicators, so that there is improper indication, thus causing an imperfect printing condition setting.
On the other hand, as a technique for specifying the characteristics of a film such as speed, type, expiration data, sensitivity, latitude, etc. binary codes have been applied which represent such characteristics using a method in which perforations are combined depending on the presence or absence thereof between sprockets extending along the edge portions of a roll of 35 mm size film (see "19223 Photographic Film Coding" RESEARCH DISCLOSURE April 1980 No. 192).
As one example of this technique applied to indicate information about the photographic paper, the following has been proposed. At the end of the photographic paper photosensitive characteristics such as quality, maker, size, etc. are represented in the form of punch marks which are convertible to electric signals. These marks are automatically read so as to match the most suitable processing with the type of the photographic paper in accordance with data stored in advance (see Japanese Laid-Open Patent Publication no. 62-286040). According to this disclosure, since the information about the photographic paper is already written in the photographic paper itself, no improper indication of the same is effected even when the photographic paper is refilled.
However, it is only possible to apply the information about the photographic paper to the end portion of the photographic paper in the above-described arrangement. Thus, when the present magazine is replaced and mounted in the course of its use by another magazine in which a photographic paper different in type from the photographic paper presently in use is loaded therein, and the photographic paper in the course of its use is employed again, a point in the course of the photographic paper becomes an end portion thereof, so that the information about the photographic paper cannot be obtained. It is therefore necessary to devise a scheme for causing the magazine to correspond to the photographic paper to be loaded therein.